\documentclass[UTF8]{ctexart}
\title{你好，world!}
\author{Liam}
\date{\today}
\begin{document}
\maketitle
\section{你好中国}
中国在 East Asia.
\subsection{Hello Beijing}
北京是 capital of China.
\subsubsection{Hello Dongcheng District}
\paragraph{Tian'anmen Square}
is in the center of Beijing
\subparagraph{Chairman Mao}
is in the center of 天安门广场。
\subsection{Hello 北京}
\paragraph{北京} is an international city。
\end{document}